Luminescent sign



Sept. 20, 1932 M. G. MORRIS 1,878,230

LUMINESCENT 'SIGN Filed Ju1yv14, 1928 2 sheets-sheet 2 Patented Sept. 20, 1932 UNITED STATES PATENTJ OFFICE MELVIN G. MORRIS, OF TAMPA, FLORIDA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO CLAUDE NEON LIGHTS, INC., OF NEW YORK, N.' Y., A CORPORATION OF NEW YORK LUMINESCENT SIGN Application led July 14,

This invention relates to improvements in luminescent signs embodying tubes adapted to be charged or filled with a part or parts of one or more of the elements of the atmosphere, and preferably a part or parts of one or more of the rarified gases of the Noble group, such as helium, neon, argon, and the like, whereby when an electrical discharge is passed between electrodes within the tube, the atmosphere or gas serves as a conducting medium and, due to ionization, gives forth a luminous glow.

ln the utilization of tubes of this character, in these luminescent signs, a comparatively high voltage is required to bring the free electrons within the tubes up to ionizing velocity. This Voltage usually ranges from 6,000 to 20,000 volts, depending upon the size and length of the tubing and the brilliancy desired. To arrive at this voltage, step-up transformers are usually employed to raise the voltage from the commercial 110 volt alternating current, (S0-cycle sources. Because of the high voltages utilized in these signs, proper insulation and installationof the tubing in the sign is a prime requisite. The illumination of signs comprising tubes such as outlined has been commercialized to quite a large extent at the present time, but the development has been retarded through the lack of ability to solve this problem of insulation. The industry is familiar with the havoc high voltage has wrought with improperly installed tubing and improvised insulation, especially in damp and rainy weather. The high voltage leaks and creeps and when it finds an outside path of conductivity, it travels over it, playing havoc and jeopardizing the life of the tube. It is commonly known that the industry has suffered through the puncturing of tubes, the shortcircuiting the insulations and the creating of fire hazards.

In view of the foregoing, the primary object of the present invention is to provide insulated receptacles or connectors that. will afford proper terminal facilities for supporting the tube of a luminescent sign, said insulator possessing features which, in combination with the peculiar electrode arrangement 1928. Serial No. 292,762.

of the tube, will practically eliminate short circuiting of the high voltage current under conditions which will result in puncturing the tube.

The insulated receptacle or connector for the tube is also designed in such fashion as to practically completely protect the electrodes of the tube from weather or moisture, thereby tending further to prevent puncturing of the tube and, in other respects, also lengthening the life of the tube.

Another object of the invention is to provide an insulated connector for the tube and its electrodes which will simplify manufacture and maintenance, meet the approval of electrical standards, and greatly facilitate the installation of the sign.

In connection with signs of this character, it is essential that the cables carrying the current to the insulator receptacles and tubing be rather rigidly supportedand a further object is to provide a supporting insulator for said cable that is especially adapted for use in connection with these luminescent signs.

With these and other objects in view, the invention consists in certain novel details of construction and combinations and arrangements of parts, all as will hereinafter be more fully described and the novel features thereof 'particularly pointed out in the appended claims.

In the accompanying drawings,

Figure 1 is a. plan view, partly in section, showing the installation of one end. of the tube of a luminescent sign;

Fig. 2 is a section on the line 2--2 of Fig. 1;

Fig. 3 is a section on the line 3--3 of Fig. 1;

Fig. 4 is a section on the line 4--4 of Fig. 1; and

Fig. 5 is a section on the line 5-5 of Fig. 1.

.As will be understood, the glass tubing 10, constituting the sign proper, is located outside of a casing 11 of any desired metal, said tubing Ahaving oiiset end portions 12 that are adapted to be supported from the 1nterior of said metal casing. In the present instance, one end portion only of the tubing and casing is shown, this being thought all that is necessary in view of the fact that the thereof and secured in the bottom of saidy bore by a bindin post screw 17 are a plurality of spring ngers 18 constituting contact members for leading in the high voltage current. Extendin from the bottom of the central bore lateral? of the insulator 13 and in alinement with binding screw 17 is an opening 19 into which the end of a cable 20 may be inserted, said cable being rovided at this end with a contact member t at may complete.

be inserted beneath bindingscrew 17 and clamped to the spring fingers 18. In its referred form, the tube 10 is provided with ya double electrode, one electrode 21 being located within the tube end and the other\ electrode 22 being placed on theexterior of said tube end. The exterior electrode 22 is at least as lon as the interior electrode 21 and might be escribed as surrounding the same for a purpose which will presently apar. This exterior electrode 22is adapted to slip on the end of the tube, the frictional engagement being such as to retain it thereon. lhe two electrodes are electrically connected together b wires 23, which lie beneath the electro e 22. With this arrangement, installation of the tube in the insulator simpl requires that the tube ends be inserte in the central bore 16 until the exterior electrode 22 is brought into engagement with the spring contact fin ers 18. The cable 20 having been connec to binding screw 17, the circuit from said cable all the way througlh to the interior electrode, is he provision of a combination interior and exterior electrode is quite advantageous for several reasons. First, the exterior electrode 22 serves as a contact member for the interior electrodez although so far as certain features of the invention are concerned, yother means might be utilized for connecting up the inner electrode 21 with the spring fingers 18. However, the use of the exterior electrode completely surrounding the tube end permits the tube to be simply ushed into the socket formed by the central re of the insulator. Another advantage of the combined electrodes is that a greater degree of luminosity is secured, as experiments have shown that the exterior electrode if used alone, will cause the tube to glow at about ofits luminosity. In other words, the two electrodes 21, 22 can be said to form a. two-part electrode, because the outer portion thereof augments the functioning of the interior part thereof so far as illumination'is concerned. The exterior portion of the electrode, or what has been termed the electrode ,22, also tends to prevent vaporization of the interior electrode 21. In addition to the foregoing, location of a portion of the `combined electrode on the exterior of the tube also eliminates puncturing of said tube. `In practice, it has been found that conductive surfaces will be formed on the interior of the insulator, as for instance, by water obtaining access to central bore 16, and under these conditions the high voltage current has a tendency to short circuit from the electrodes to said conductive surface of the insulator. In the present sign, however, this puncturing of the tube is prevented because of the provision of the external electrode. As the current will follow the path of least resistance, any short of the circuit will take place between the exterior electrode and any conductive surface on the insulator instead of such short taking place between the interior electrode and said surface, as this would require the current to pass through the glass tube.

In view of the possibility of the shorting of the circuit, the tube supporting insulator of the present sign, together with the tube itself, are conjointl provided with means which will substantially eliminate all possibility of water gaining access to the central bore 16. This is preferably accomplished by having the end of the insulator into which the tube is fitted provided with an overhanging ledge 24 and a concentric recess 25, so that an film of water that may tend to form on this exposed surface of the insulator would necessarily be broken at the very edge of ledge 24. In this way, it is impossible for a continuous film of water to form on the insulator extendin from the surface of the metal casing 11 o the sign into the interior of the insulator. The revention of such continuous film between tllese points is essential because such a film of water would form an ideal conductor for the current being utilized in the sign that would have a strong tendency to cause short circuiting from the electrodes to the metal of casing 11. To further prevent water passin into central bore 16 and coming in contact with the spring fingers 18 or the exterior electrode 22, the surface of bore 16 within the insulator is formed with an annular trough or depression 26 and means for draining from said trough any moisture or water that might collect therein. Such draina e is preferably secured b the provision o one or more openings 27 extending from said trough outwardly through the insulator to the exterior surfaces thereof. In combination with these means for preventing access of water to the interior of the insulator, there is also formed on the end portion of the tube a series of annular ribs or projections 28 from which any water passing along the tube will drip, instead of continuing longitudinally of said tube until it comes into contact with the electrode or contact fingers. It might be added that trough 26 is necessarily located at some point in the interior of the insulator between the end of the latter and the electrode 22.

In signs of this kind, it is also desirable to rigidly support the high tension cable 20 within the casing 11 and. it is also necessary that such cable be as remote as possible from any conductive material, such as the metal casing. For this reason, there are provided in the present sign one or more elongated insulators 29 having a central bore extending therethrough into which fits a stem 30 on whose outer end there is a cable receiving eye 31. In the end face of said insulator 29 there is a transverse groove 32 for reception of the cable 20, this end of the insulator also being formed with a depression into which a portion, at least, of the eye 31 may seat. At its opposite end, said insulator is formed with a substantially flat surface adapted to abut against the metal of casing 11. To secure said insulator in place within the sign casing, the latter is perforated for a screw 33, Whose head engages against the sign casing and Whose shank is threaded into the end of stem 30. With this arrangement, by taking up on the screw 33, the insulator will not only be clamped against the sign casing, but, in addition, tightening of the 'screw will effect a clamping of the cable 2O in the cable groove 32 at the opposite end of the insulator. In other words, the screw serves two functions, i. e., that of screwing the insulator 1n place, and also clamping the cable tightly against said insulator.

It might be added that provision of the annular ribs or projections 28 on end l2 of the tube not only results in breaking any water column that might tend to form between outside moist surfaces and the dry electrode at the interior of the insulator, thereby preventing the formation ofa path of conductivity, but, in addition, the static is reduced and the corona loss of the tubes in damp weather is kept at a minimum.

While various forms of electrodes might be used in the present instance, it is preferred that commercial pure copper or nickel mesh material in cylindrical form be employed, as the same is capable of expanding to accommodate variations in the diameter of the end of the tube. Commercial material may be utilized, as stated, because it is not necessary that the electrodes be totally deprived of occluded gases. Electrodes having an area of less than 1.5 square decimeters per ampere have been found to give satisfactory results.

What I claim is:

1. In a luminescent sign, an insulator having a longitudinal bore extending from one end thereof, a pluralit of contact members on the interior of sai bore, a luminescent tube having a contact member on the exterior thereof frictionally engaging the contact members within the bore of said insulator, and a binding post screw for securing said contact members within the bore of said insaid tube for diverting water collecting onthe exposed portion of said tube away from said electrode, and means formed on the end of said insulator for diverting water from said electrode.

3. In a luminescent sign, an insulator having a central bore opening at one end thereof, a tube having one end inserted in said bore, an electrode at the end of said tube within the bore of said insulator, means formed on said .tube for diverting water collecting on the exposed portion of said tube away from said electrode, and means formed on the end of Said insulator for diverting water from said electrode, the water diverting means on the tube consisting of a series of annular ribs or projections on the exterior of the end of said tube adjacent said insulator.

4. In a luminescent sign, an insulator having a central bore opening at one end thereof, a tube having one end inserted in said bore, an electrode at the end 0f said tube within the bore of said insulator, and means formed on said tube for diverting water on the exterior of said tube away from said tube, the end surface of said insulator having a depression there'in for rupturing any film of water extending from the exterior of the insulator into the interior surface of said bore.

5'. In a luminescent sign, an insulator having a central bore opening at one end thereof, a tube having one end inserted in said bore, an electrode at the end of said tube within the bore of said insulator, the end surface of said insulator having-1a depression therein for rupturing a film of water extending from the exterior of said insulator into the interior surface of said bore, and a series of annular ribs or projections on the exterior 'of the end of said tube adjacent said insulator.

6. In a luminescent sign, an insulator having a central bore opening at one end thereof, a tube having one end inserted in said bore,

an electrode at the end of said tube within the bore of said insulator, the end surface of said insulator having a depression therein for rupturing a film of water extending from the exterior of said insulator into the interior surface of said bore and the interior surface of said central bore having a depression extending around the same for. collecting water passing into said bore, and means for draining water collecting in said depression to the exterior of said insulator.

7. In a luminescent sign, an insulator having va central bore extending inwardly from one end thereof, a contact member vwithin said bore, a tube having one end portion supported in said bore, an electrode on the exterior of said tube end'engaging said contactl member, and means formed in said insulator between the end thereof and said electrode for draining water or other moisture from the interior of said insulator.

8. In a luminescent sign, an insulator having a central bore extending inwardly from one end thereof, a contact member within said bore, a tube having one end portionsupported in said bore, an electrode on the exterior of said tube end engaging said contact member, said insulator having a depression extending around the surface of said bore between said electrode andthe end of said insulator, and means for draining any moisture or water collecting in said depression to the exterior of said insulator.

9. In a luminescent sign, an insulator having a central bore extending inwardly from one end thereof, a Contact member within said bore, a tube having one end portion supported in said bore, an electrode on the exterior of said tube end engaging said contact member, said insulator having a--depression extending around the surface of said bore between said electrode and the end of said insulator, said depression having lapertures in the bottom thereof leading tothe exterior surface of said insulator.

10. An insulator having a lcentral bore opening at'one nd thereof for the reception of a luminesci t tube, a contactlmember in said bore, means at the` end of said 'Insulator for rupturing a film of water extending from` the outer surface to the inner surfaceof said insulator, the inner surface of said insulator having a depression therein for collecting Water draining into said bore, and means for draining waterfrom said depression to the exterior of said insulator.

,MELVIN G. MORRIS. 

